1. Field of the Invention
The present invention relates to an electric power generation control apparatus, to be connected to an external controller composed of any one of various types of vehicle interface circuits, capable of controlling the generation of electric power of a vehicle alternator mounted on a vehicle.
2. Description of the Related Art
There is a well-known conventional electric power generation control apparatus capable of receiving through an external signal receiving terminal a power switch-on signal transferred from an external controller connected to the electric power generation control apparatus, and thereby initiates the control of the generation of electric power of a vehicle alternator mounted on a vehicle. For example, such a control technique of the generation of electric power in the vehicle alternator has been disclosed in the Japanese patent laid open publication No. JP 2003-88191. (see pages 5 to 14 and FIGS. 1 to 8)
When a user or a driver of a vehicle replaces a vehicle alternator and an electric power generation control apparatus mounted on a vehicle with new ones due to various reasons that the new assembly units do not match the vehicle interface circuit. It may be, that the fault lies with the electric power generation control apparatus in that it is not adopted in circuit type to a vehicle interface circuit incorporated in an external controller. This unmatched assembling causes that a control signal cannot be transferred correctly from the external controller to the electric power generation control apparatus.
For example, there are various unmatched assembling situations in which not needed the external controller is composed of a vehicle interface circuit made of a pull-up circuit, where the electric power generation control apparatus is replaced with a new electric power generation control apparatus having a receiving circuit adopted to a pull-down circuit, or in which the external controller has the vehicle interface circuit made of a pull-down circuit and the electric power generation control apparatus is replaced with a newly installed electric power generation control apparatus having a receiving circuit adopted to a pull-up circuit. In those unmatched assembling situations, because the electric power generation control apparatus inputs only a control signal of a high level or only a control signal of a low level, the receiving circuit in the electric power generation control apparatus cannot receive the control signal such as an electric power switch-on signal transferred from the external controller, and thereby cannot initiate the control of the generation of electric power of the vehicle alternator. In circumstances of bad maintenance or conditions for a vehicle or in emergencies, such an unmatched assembling can happen, in which a user or a driver of a vehicle replaces a vehicle alternator and an electric power generation control apparatus mounted on the vehicle with new ones which do not adopt the circuit configuration of the vehicle interface circuit of the external controller, and when the vehicle travels long distances, a battery mounted on the vehicle becomes discharged and is finally dead because the electric power generation control apparatus cannot correctly receive the control signals transferred from the external controller.
In order to avoid such a drawback while not considering the occurrence of unmatched assembling, namely regardless of any occurrence of unmatched assembling between the electric power generation control apparatus and the external controller, it is necessary to have plural receiving circuits in the power generation control apparatus corresponding to various types of vehicle interface circuits. This increases design work, manufacturing cost, and distribution cost of the power generation control apparatus.